use boxlayout from lazycore

vendor/github.com/samber/lo/math.go

@@ -0,0 +1,74 @@
+package lo
+
+import "golang.org/x/exp/constraints"
+
+// Range creates an array of numbers (positive and/or negative) with given length.
+// Play: https://go.dev/play/p/0r6VimXAi9H
+func Range(elementNum int) []int {
+	length := If(elementNum < 0, -elementNum).Else(elementNum)
+	result := make([]int, length)
+	step := If(elementNum < 0, -1).Else(1)
+	for i, j := 0, 0; i < length; i, j = i+1, j+step {
+		result[i] = j
+	}
+	return result
+}
+
+// RangeFrom creates an array of numbers from start with specified length.
+// Play: https://go.dev/play/p/0r6VimXAi9H
+func RangeFrom[T constraints.Integer | constraints.Float](start T, elementNum int) []T {
+	length := If(elementNum < 0, -elementNum).Else(elementNum)
+	result := make([]T, length)
+	step := If(elementNum < 0, -1).Else(1)
+	for i, j := 0, start; i < length; i, j = i+1, j+T(step) {
+		result[i] = j
+	}
+	return result
+}
+
+// RangeWithSteps creates an array of numbers (positive and/or negative) progressing from start up to, but not including end.
+// step set to zero will return empty array.
+// Play: https://go.dev/play/p/0r6VimXAi9H
+func RangeWithSteps[T constraints.Integer | constraints.Float](start, end, step T) []T {
+	result := []T{}
+	if start == end || step == 0 {
+		return result
+	}
+	if start < end {
+		if step < 0 {
+			return result
+		}
+		for i := start; i < end; i += step {
+			result = append(result, i)
+		}
+		return result
+	}
+	if step > 0 {
+		return result
+	}
+	for i := start; i > end; i += step {
+		result = append(result, i)
+	}
+	return result
+}
+
+// Clamp clamps number within the inclusive lower and upper bounds.
+// Play: https://go.dev/play/p/RU4lJNC2hlI
+func Clamp[T constraints.Ordered](value T, min T, max T) T {
+	if value < min {
+		return min
+	} else if value > max {
+		return max
+	}
+	return value
+}
+
+// SumBy summarizes the values in a collection using the given return value from the iteration function. If collection is empty 0 is returned.
+// Play: https://go.dev/play/p/Dz_a_7jN_ca
+func SumBy[T any, R constraints.Float | constraints.Integer](collection []T, iteratee func(T) R) R {
+	var sum R = 0
+	for _, item := range collection {
+		sum = sum + iteratee(item)
+	}
+	return sum
+}